> The fact that one engineer installed a site, began operating the app, > then saw it become corrupt minutes later rules out power loss or hard > resets in at least that case. An operating system level problem should > have been noticed by now given it's Windows XP... And the file is > locally held too.
I don't know how Windows's disk cache works but theoretically when you set synchronous to OFF (0) OS can write database pages to disk in any order it likes, disregarding the order SQLite requires. So while one process writes those pages, another process can read those pages and because of random writing order second process can read inconsistent data, meaning it sees corrupted database. Pavel On Wed, Apr 13, 2011 at 7:14 AM, James Green <james.mk.gr...@gmail.com> wrote: > Yep we've read through that. > > Several of the possibilities are difficult to rule out of course. They > just seem highly unlikely (!) given the rate of corruption across our > sites. > > The fact that one engineer installed a site, began operating the app, > then saw it become corrupt minutes later rules out power loss or hard > resets in at least that case. An operating system level problem should > have been noticed by now given it's Windows XP... And the file is > locally held too. > > Is it possible that we're seeing something nasty occurring as a result > of anti-virus software perhaps? I might expect a higher rate of > corruption if so. > > The only avenue apparently open to us is to use WAL mode. Would WAL + > sync=normal provide a much better resistance to corruption? We > (probably) don't care about losing the last set of SQL statements. > > sync=full does not work well for our app (no transactions). Far too slow. > > James > > On 13 April 2011 11:47, Richard Hipp <d...@sqlite.org> wrote: >> On Tue, Apr 12, 2011 at 5:15 AM, James Green <james.mk.gr...@gmail.com>wrote: >> >>> My question is does anyone have pointers >>> to help us isolate the problems we are seeing. >>> >> >> http://www.sqlite.org/howtocorrupt.html >> >> -- >> D. Richard Hipp >> d...@sqlite.org >> _______________________________________________ >> sqlite-users mailing list >> sqlite-users@sqlite.org >> http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users >> > _______________________________________________ > sqlite-users mailing list > sqlite-users@sqlite.org > http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users > _______________________________________________ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
